The technical field generally but not exclusively relates to fluid injection or spraying, and more particularly relates to fluid injection such as fuel injection where some fluid passages are inactive in some modes of operation. Inactive fluid passage(s) may be found in equipment for many reasons including, but not limited to: a pilot injector which is utilized for low power operation and may be turned off as required at higher power; staged fuel injector(s) which may be turned on and off based upon desired operating parameters or for emissions considerations; fuel injectors utilized for operation on different types of fuel either simultaneously or alternatively; and adding or switching between chemicals for a sprayer or cleaning nozzle. During times that a fluid passage is inactive, hot combustion products, fuel, or other injected chemicals can enter the inactive passages. Also, an inoperative fluid passage may have stagnant residual fluid that, if exposed to temperature, chemicals, or other contaminants may be altered, solidify, or cause corrosion. Further developments are desirable in this area.